Microfluidics with PDMS is a technology that is particularly suited for cell culture and that can be employed efficiently to move experiments of cell biology and biophysics down to to single cell analysis. We will show several applications of microfluidics to dedicated to cell biology. In a first part, in neuroscience, we will present a device that gathers compartmentalized neuron culture circuits with a dedicated Micro Electrode Array (MEA) to study both axon regeneration and stimulation techniques but also axonal vesicle transport and trafficking. A second part of the presentation will focus on microfluidics for hemophysics, where artificial micro vascularization are developped to study blood rheology and shear thinning phenomenons in blood circulation.